Dishwashing machine



March 21, 1933. w. HILPERT ET AL 1,902,237

DISHWASHING MACHINE Filed Feb. 5, 1930 Willis 5- HZ ZpeT'i- Patented Mar. 21, 1933 UNITED STATES PATENT OFFICE WILLIS S. HILPERT, OF wnmmxa, AND EDGAR S. STODIDARD, OF BERWYN, IIIILINOIS, ASSIGNORS TO, THE GONO'VER COMPANY, OF CHICAGO, ILLINQIS, A CORPORATION OF rumors msnwasnme mach-inn This invention relates to coated holders which are adapted to hold and position ar ticles for treatment and it particularly relates to coated dishwashing machine racks and similar structures.

Dishes, cups, glasses and other objects treated and cleansed in dishwashing machines are readily breakable and comparatively fragile. It is very important that when they are placed in a rack or holder they are not subjected to stresses, strains or impacts, which tend to break, chip or crackthem. Since the racks or holders are usually rigid and not readily yieldable, it has been found desirable to cushion these structures by means of a coat- In addition the holding structures or racks 1 are subjected to conditions which tend to cause deterioration or corrosion. The racks holding the dishes are not only subjected to contact with abrasive objects, such as the dishes, whlch tend to flex and bend the wires, but in addition are subjected to the, action of detergent and cleansing liquid mixtures of temperatures near the boiling point of water. If the structure is composed of a material which is not very resistant to these conditions, it is desirable to provide it with a protective coating. Normal protective coatings which may be applied will tend. to be broken, ruptured or worn away by contact with the dishes or due to the flexing of the wires when the dishes are laced in position and due to the action of t e detergent liquids. It has therefore been found necessary to apply a coating which will stand up under exceptionally severe conditions.

The object of this invention is to provide a new and improved coating for dishwashing machine racks, and a more desirable coating than has hitherto been applied.

Another object of this invention is to provide a new coating for dishwashing machine racks which will serve to cushion the dishes plates, cups, glasses and other objects placed therein.

A further object of the present invention is to provide a protective coating for the rack structure which-will protect it from deterioration and corrosion.

chine rack construction illustrating the structure described in'the present invention, Fig. 1 being a top view and Fig. 2 being a side sectional view. The frame is formed of a series of conjoined wires 10 shaped and connected in any suitable manner to form a holder suitable for supporting the table articles to be cleansed. The frame so formed is covered with a coating 12, preferably of rubber. It is obvious that the component pieces of the rack structure may be made in varying shapes and connected in different manners to afford the necessary rigidity as described and shown in the copending applications Serial Nos.

271,681, 293,197 and 354,209, filed April 21,

1928, July 16, 1928 and April 11, 1929, respectively.

It has been found that if certain organic materials are plated or attached to metallic structures of the nature of dishwashing machine racks under predetermined conditions a very satisfactory coating is obtained. The various factors which must be taken into consideration are the chemical composition,

the resiliency and plasticity, the thickness and the continuity of the coating, and also the diameter or size of the elements or wires forming the supporting structure, and the chemical composition of the base material.

The preferred coating materials are rubher or similar organic materials; The present invention will be-particularly described in its application to rubber coated dishwashing machine racks, but it is to be understood that it is not restricted to such coatings and 96 it is sufiiciently broad to include other coatings which may be applied with similar results. Among materials which may be considered within the purview of the invention are plasticized and tanned gelatin (that is to say gelatin which has been rendered insoluble and rendered plastic, as by the addition of formaldehyde and glycerine), or other proteins and nitrogenous colloids,

properly treated and processed resins, both natural and synthetic, oxidized and/or sulphurized oils, and so forth.

When rubber is utilized, it is very important that the rubber coating be free of excessive sulphur. As a general rule the rubber should be substantially or in large part free of any volatile, readily decomposable sulphur compounds which will be affected by the temperature and chemical composition of the detergent or cleansing liquids. The rubber coating should not be substantially thermoplastic within the range from ordinary atmospheric temperature to near the boiling point of water.

The base material, which is usually metallic in character, on the other hand, should be fairly light weight, durable and elastic so as to permit of a reasonable amount of flexing. Although metallic materials are preferred, non-metallic materials may be utilized if desired. Iron and steel are usually most readily available. When the base is made of a corrodible iron material, such as black or basic process iron, it is desirable to provide a coating which will protect the metal structure. When such iron base materials are utilized, it has been found satisfactory in certain instances to coat these iron base materials with cadmium, zinc, tin or some other metal which is less readily corrodible than the iron metal base before the application of the rubber coating.

The framework of the rack structure is composed of metals or other structural materials in the form of wire, rod, ribbons, plates, and so forth. When wire or rod is used, it has been found very satisfactory in one embodiment of the invention to utilize a diameter or thickness of between about 0."05.and 0."3 or more, preferably between about 0."1 and 0. '2. Wire ranging between about 0."1 to 0."15 or between about 0."1 and 0. '2 has been found quite satisfactory as a base for rubber or organic coatings of the character particularly covered by the present invention.

In a preferred embodiment of the invention the organic coating may be applied continuously over the entire metallic structure in such a manner that there is substantially no relative movement between the metallic base and the coating. In addition, the coating should desirably be of such a thickness, flexibility and elasticity as to permit a substantial amount of stretching or bending of the same Without tearing itloose from the metallic base and without causing a rupture in its surface. It is also desirable that the thickness of the elements of the final rack structure be regulated with a view toward economy of space utilization and so that there is no substantial interference with the spray projection or cleansing action of the liquid in the machine. It has been found that the combined thickness of the wire and rubber coating should preferably be not much over O."25-0."3. A coating of approximately has been found very satisfactory, and, as a general rule, coatings varying from about 1/64" to 5/64" or from about 1/64 to 9/64" are satisfactory for the purpose of the present invention.

As mentioned before, the coating is preferably continuous and it is most desirably at ached to the metallic base wire in such a manner that there is substantially no relativeginovement between the metallic base and the fcoating. The rubber or the coating material may be applied by spraying or brushing the rack with solutions of the rubber material in volatile or other removable liquid materials. It may also be applied by dipping the metallic structure one or more times into a bath of the coating material. A very satisfactory method of application has been found to consist in electroplating the rubber upon the metallic base. Other procedures may also be employed.

It is desirable that the final coating be an aggregate colloidal mass forming a continuous cushion over the entire metallic structure. As stated before, the composition of the material should be so regulated that it will not be substantially affected by detergent liquids within the range between atmospheric temperature and the boiling point of water. The coating as actually applied or placed upon the metallic structure should be flexible and resilient, and if it is to serve as a protective coating for the metal base, it should also be non-porous and of such a character that it retain its non-porous characteristics under action of the heat, water and cleansing materials to which it is subjected in use. The coating should also be sufficiently resilient to prevent chipping or rupturing of the dish or other object placed in the rack structure. Although it is desirable that the coating be substantially continuous over all parts which are contacted with or serve to support the dishes and parts to be cleansed, it is possible to vary the thickness of the rubber coating in different sections of the rack. As a general rule, the thickness of the rubber coating will be substantially uniform throughout the entire rack structure.

The color of the coating may vary and black rubber has been satisfactorily employed. Under many conditions gray or white rubber coatings may also be employed. The coloring of the rubber may be accomplished before, during or after attachment of the rubber to the rack structure.

It is apparent that many modifications and changes may be made within purview of the present invention. It is intended to include all such modifications and changes therein.

What is claimed is:

of wires forming holders for the various articles to be cleansed, and a cushioning coating thereon, said coating consisting of a layer of lasticized and tanned gelatin.

n testimony whereof we have subscribed our names to the foregoing specification and claim.

WILLIS S. HILPERT. EDGAR S. STODDARD. 

